Liquid crystal displays able to show alphanumeric and/or graphical information in various colors are well known in the art. Such liquid crystal color displays are used in avionics, computers, telephones, medical imaging, vehicles, and various other applications. In many cases the displayed colors may convey functional information. For example, and not intended to be limiting, text, numbers, and/or symbols, or a combination thereof may signify a substantially ‘safe’ condition when presented in green, a ‘caution’ condition when presented in yellow or amber, and a potential ‘danger’ condition when presented in red. In such instances, the color of the image is intended to convey information to the user, in addition to or as a supplement to the information provided by the content of the image. Thus, color fidelity including color fidelity as a function of viewing angle or other factors, can be important. For example, if the color perceived by the viewer changes depending upon, for example, viewing angle, or the image contrast or luminance, this can potentially lead to mistaken interpretation of the displayed information. In addition, various users desire that the colors presented conform to particular standards. Thus, having a large number of color choices may also be important.
While present day color liquid crystal displays are very useful they do suffer certain drawbacks. For example, the viewing angle over which color fidelity is reasonably preserved may be undesirably narrow, and/or the absolute color provided by the display can vary depending upon the drive intensity, and/or the number of possible colors that can be displayed may be undesirably limited, and/or the display brightness may be weak and insufficient to permit easy viewing in sunlight or other bright light conditions, and so forth. Further, color fidelity, color choice, luminance or brightness, viewing angle, and other properties often mutually interact so that prior art approaches for improving one property may cause degradation in another property.
Accordingly, it is desirable to provide an improved color generation apparatus and method for color liquid crystal displays, especially for displays suitable for use in avionics systems. In addition there is an ongoing need to provide a display and method of driving the display that maximizes the number of available color choices and useful viewing angles, without significantly detracting from the display brightness and life. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.